In a conventional personal computer, data access is performed by use of a recording medium, such as a magnetic disk. In this case, the input/output of a magnetic disk device is controlled by an operating system (OS) built into the personal computer.
When the personal computer has access to a device for an optical recording medium, which is a special recording medium, exclusive software other than the above-mentioned OS is incorporated into the personal computer in order to control the input/output of the device for the optical recording medium.
In the case of access to the optical recording medium in the above-mentioned conventional system, the following problems arise:
(1) Since the software for access to the optical recording medium is very large, if the software is incorporated into the personal computer, the burden on the memory size, processing time, etc. of the personal computer becomes heavy;
(2) Conventional recording media are erasable, while most optical recording media are not erasable. Therefore, it is impossible for the personal computer to treat the optical media in the same manner as the conventional media;
(3) In order to have access to the optical recording medium, the personal computer is required to use special I/O functions or commands;
(4) Every time access is requested from the personal computer, access to the optical recording medium is performed. Therefore, loss of time is caused;
(5) Since the optical recording medium is special, it is required to consider how to cope with errors in the medium; and
(6) It is required to build a file system which makes the best use of the characteristics of the optical recording medium. DISCLOSURE OF INVENTION
In order to solve the above problems, there is provided a control board for access to an optical recording medium, which is connected to a main body of a personal computer which has access to the optical recording medium through an optical recording medium read/write device, and for enabling access to the optical recording medium in the same state as an existing magnetic disk device and the like by use of the optical recording medium read/write device. Furthermore, the control board is composed of a directory unwinding processing station, various types of interface processing stations, a retrieval processing station, a data transfer/receiving processing station, a data input/output processing station and a directory update processing station.
Such composition enables access to the optical recording medium in the same manner as other existing media, by utilizing commands, I/O functions and so on in the computer body.
In addition, compared with access to the optical recording medium read/write device with only software installed in the computer body, it is possible to reduce the burden on the computer body in memory size and processing time.
In a preferred embodiment, a control board of the invention can be installed in a slot of the computer body.